厦门地区木材平衡含水率的研究

STUDIES ON THE EQUILIBRIUM MOISTURE CONTENT OF WOOD IN XIAMEN REGION

木材平衡含水率与气候、特别是与相对湿度和温度的变化密切相关。Hawley、Kollmann、及UyluHlskuǔ都曾进行这方面的工作。我国梁世镇等在1963年提出We=a+bφ+cφt^2的曲线回归方程,表示木材平衡含水率与空气温湿度之间的变化规律,并据此分别绘出适用于北京、芜湖和福州等地的t-φ-We图。孙令坤、龚定太也分别引用到呼和浩特、十堰的木材平衡含水率研究。作者根据厦门测定的数据,通过IBM电子计算机进行运算,得出We=a+bt+cφ的线性回归方程。

The equilibrium moisture contents (EMC) of 19 species in both outdoor and indoor conditions were determinded in Bantou Protective Forest Farm of xiamen during 1985—1986. The results show that the mean value of EMC in outdoor condition is 15.1％ and 12.4％ in indoor condition. The maximum EMC is found in June, while the minimum in October. Among the 19 species, the greatest value of EMC in outdoor condition is Gryptomeria fortunei (17.1％~) and the lowest is Alniphyllum fortunei (12.0％), while in indoor condition they are respectively Eucalyptus robusta (14.3％) and Paulownia fortunei (10.7％). Values of EMC for every month in outdoor condition are obviously higher than in indoor condition, with the exception of Alniphyllum fortunei. The EMC of wood varies with the relative humidity and temperature of the surrounding air, it is further found that there exists an extremely significant relationship which can be expressed in both linear and curvilinear regression equations. However, the correlative coefficient (R) and variance ratio (F) of the linear equation are slightly higher than those of the curvilinear equation. The former is likely more precise and simple in calculation than the later. It is considered that the linear equation seems to be more suitable than the curvilinear equation to express such a relationship. Finally, two graphes of t-φ-we for xiamen region are drawn up on the bases of both linear and curvilinear regression equations.